Lithium-ion (Li-ion) batteries tend to become dangerous when they are charged by high charge voltage and charge current at high temperatures. Therefore, the Japan Electronics and Information Technology Industries Association (JEITA) standard addresses safety requirements and battery-charger solutions to avoid the human safety risk.
In the JEITA standard, the charge voltage and charge current need to be decreased at high temperatures or low temperatures. In the conventional art, analog comparators or software solutions are used to adjust the charge voltage and charge current at high/low temperatures. However, the analog comparators need too much die area, and the temperature threshold settings are not flexible; and the software solutions still have risk if the software hangs up at high/low temperatures.